Black tank smell when coach not level.

[Rusty Kramer]

I installed the 360 vent over the winter due to sewer smell last year when flushing toilet. Using the coach all day Saturday and no smells at all.

Got home today and pulled in my shop parking lot to unhook the trailer. Unfortunately I don't have any level area in the parking lot. So coach is front and left side low. Got out unhooked the trailer. 10 minutes or so, went back in the coach and had black tank smell. I treat the black tank with chemical. Now the black tank was not full probably not much water. Where is this coming from and does the off level have anything to do with this? I thought the only vent/opening to the tank was the roof vent or toilet itself when flushing?

I dumped a blue bottle in it and a couple gallons of water and parked at the house to unload it. No smell but it is level...

Thanks in advance for any info.

[ByeTheWay]

Several years ago I realized I had more smell when using the blue stuff or any other chemicals. That is not to say the black tank does not smell, but I believe they accent the smell. When you say you added more blue the smell was gone but for how long?

We don't use any chemicals. And can go up to 2 weeks without an issue. Even in summer. We never flush with the vent or exhaust fan on. That will pull the smell right out.



If you tank is sealed, the only time the roof vent works is when the toilet is open. Otherwise it is like sucking air out of a pop bottle.



No vent fan, no chemical, no smell.

[Rusty Kramer]

Originally Posted by ByeTheWay

Several years ago I realized I had more smell when using the blue stuff or any other chemicals. That is not to say the black tank does not smell, but I believe they accent the smell. When you say you added more blue the smell was gone but for how long?

We don't use any chemicals. And can go up to 2 weeks without an issue. Even in summer. We never flush with the vent or exhaust fan on. That will pull the smell right out.



If you tank is sealed, the only time the roof vent works is when the toilet is open. Otherwise it is like sucking air out of a pop bottle.



No vent fan, no chemical, no smell.

Thanks for the response, but I was not flushing the toilet. Just parked the coach (off level) Not sure if off level matters , shut it off. got out to unhook the trailer. went back in the coach and the smell was there.

[Captjake1]

I had a horrible smell after driving uneven roads, usually when I had fluid in the tank.
I determined it to be the p trap in my shower was getting sucked dry by the fluid in my grey tank.
Add water to trap and all good. In my case, I can't find a more permanent solution. Grey water in my opinion smells worse than black.

[RamiDav]

When we first bought our coach there was no smell but after a short time

we did , couldn't even tell where it was coming from .
Finally I pulled the commode and found the foam gasket was goofed up ,
sort of folded over on one edge .

I believe they worked on the elect toilet and didn't lift and put the toilet
straight down .
Installed a new gasket , smell was gone .


I run the fan when I'm in there but turn it off before flushing .
If you don't turn it off you'll be sorry .

[Podivin]

Keep in mind that gray tanks can smell as bad as the black tank, so maybe expand your search to that to see if that's the culprit.

[irishguy]

You should consider using "Happy Campers Holding Tank Treatment" in your black and gray tanks. It is a white odorless powder. It works unbelievably well. You won't have to worry about tank odors anymore.

[Rusty Kramer]

Originally Posted by Captjake1

I had a horrible smell after driving uneven roads, usually when I had fluid in the tank.
I determined it to be the p trap in my shower was getting sucked dry by the fluid in my grey tank.
Add water to trap and all good. In my case, I can't find a more permanent solution. Grey water in my opinion smells worse than black.

OK thanks Captjake, That relates to my off level situation causing the smell to happen.

[Rusty Kramer]

Originally Posted by irishguy

You should consider using "Happy Campers Holding Tank Treatment" in your black and gray tanks. It is a white odorless powder. It works unbelievably well. You won't have to worry about tank odors anymore.

I will try it thanks!

[zo66]

Originally Posted by Rusty Kramer

I installed the 360 vent over the winter due to sewer smell last year when flushing toilet. Using the coach all day Saturday and no smells at all.



Got home today and pulled in my shop parking lot to unhook the trailer. Unfortunately I don't have any level area in the parking lot. So coach is front and left side low. Got out unhooked the trailer. 10 minutes or so, went back in the coach and had black tank smell. I treat the black tank with chemical. Now the black tank was not full probably not much water. Where is this coming from and does the off level have anything to do with this? I thought the only vent/opening to the tank was the roof vent or toilet itself when flushing?



I dumped a blue bottle in it and a couple gallons of water and parked at the house to unload it. No smell but it is level...



Thanks in advance for any info.

Hey Rusty,

Did you install one or two of the 360 siphon vents?

As others have mentioned, the grey tank can smell as bad or worse than the black tank, and therefore the grey tank vent can benefit from the upgrade as well.

We have also experienced the shower pee trap issue after the coach was in storage for a long period of time without use. As John said, it's a easy fix to run water and fill up the pee traps

[Rusty Kramer]

Originally Posted by zo66

Hey Rusty,

Did you install one or two of the 360 siphon vents?

As others have mentioned, the grey tank can smell as bad or worse than the black tank, and therefore the grey tank vent can benefit from the upgrade as well.

We have also experienced the shower pee trap issue after the coach was in storage for a long period of time without use. As John said, it's a easy fix to run water and fill up the pee traps

zo66 Only one but I only have one tube on the roof so i figured they must be connected somewhere in the coach. not sure how to keep the Pee traps full since we used all the drains at some point during the weekend. I am going to try the happy camper powder since we dry camp and have to drive to a dump station at a campground when we get back home and that does not always happen after each trip.

[Captjake1]

Originally Posted by Rusty Kramer

zo66 Only one but I only have one tube on the roof so i figured they must be connected somewhere in the coach. not sure how to keep the Pee traps full since we used all the drains at some point during the weekend. I am going to try the happy camper powder since we dry camp and have to drive to a dump station at a campground when we get back home and that does not always happen after each trip.

I only have 1 roof vent as well. The gray tank vents under the sinks through AAV's, at least on ours.
I surmise that when our gray tank is more than half full and we drive on roads that either curve a lot or tilt, the liquid creates a suction on the water the the shower pee trap, pulling the water out and into the tank.
I don't think the AAV's allow air in fast enough to compensate, or , that the shower trap being the lowest contributes.
Like said, it doesn't happen all the time, but occasionally. Wife runs back and dumps a glass of water in the shower and it clears up.
I wish I had a fix, but can't find a permanent one....short if an old fashioned tub plug.
To keep the water from evaporating storage, pour a little vegetable oil in the trap...it won't evaporate and will seal it until next use.